Clip accelerated descendants of an accelerated layer having border radius and clip overflow

Source/core/rendering/CompositedLayerMapping.cpp

 /*
  * Copyright (C) 2009, 2010, 2011 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 452 matching lines @@
 
     updateScrollParent(scrollParent);
     updateClipParent(m_owningLayer->clipParent());
 
     if (layerConfigChanged)
         updateInternalHierarchy();
 
     if (updateMaskLayer(renderer->hasMask()))
         m_graphicsLayer->setMaskLayer(m_maskLayer.get());
 
-    bool needsChildClippingMask = (renderer->style()->hasBorderRadius() || renderer->style()->clipPath()) && isAcceleratedContents(renderer);
-    if (updateClippingMaskLayers(needsChildClippingMask))
-        m_graphicsLayer->setContentsClippingMaskLayer(m_childClippingMaskLayer.get());
+    bool hasChildClippingLayer = compositor->clipsCompositingDescendants(m_owningLayer) && (hasClippingLayer() || hasScrollingLayer());
+    bool needsChildClippingMask = (renderer->style()->clipPath() || renderer->style()->hasBorderRadius()) && (hasChildClippingLayer || isAcceleratedContents(renderer));
+    if (updateClippingMaskLayers(needsChildClippingMask)) {
+        if (hasClippingLayer())
+            clippingLayer()->setMaskLayer(m_childClippingMaskLayer.get());
+        else if (hasScrollingLayer())
+            scrollingLayer()->setMaskLayer(m_childClippingMaskLayer.get());
+        else if (isAcceleratedContents(renderer))
+            m_graphicsLayer->setContentsClippingMaskLayer(m_childClippingMaskLayer.get());
+    }
 
     if (m_owningLayer->reflectionInfo()) {
         if (m_owningLayer->reflectionInfo()->reflectionLayer()->hasCompositedLayerMapping()) {
             GraphicsLayer* reflectionLayer = m_owningLayer->reflectionInfo()->reflectionLayer()->compositedLayerMapping()->mainGraphicsLayer();
             m_graphicsLayer->setReplicatedByLayer(reflectionLayer);
         }
     } else {
         m_graphicsLayer->setReplicatedByLayer(0);
     }
 
@@ skipping 150 matching lines @@
             m_graphicsLayer->setNeedsDisplay();
     }
 
     // If we have a layer that clips children, position it.
     IntRect clippingBox;
     if (GraphicsLayer* clipLayer = clippingLayer()) {
         clippingBox = clipBox(toRenderBox(renderer()));
         clipLayer->setPosition(FloatPoint(clippingBox.location() - localCompositingBounds.location()));
         clipLayer->setSize(clippingBox.size());
         clipLayer->setOffsetFromRenderer(toIntSize(clippingBox.location()));
+        if (m_childClippingMaskLayer && !m_scrollingLayer) {
+            m_childClippingMaskLayer->setPosition(clipLayer->position());
+            m_childClippingMaskLayer->setSize(clipLayer->size());
+            m_childClippingMaskLayer->setOffsetFromRenderer(clipLayer->offsetFromRenderer());
+        }
     }
 
     if (m_maskLayer) {
         if (m_maskLayer->size() != m_graphicsLayer->size()) {
             m_maskLayer->setSize(m_graphicsLayer->size());
             m_maskLayer->setNeedsDisplay();
         }
         m_maskLayer->setPosition(FloatPoint());
         m_maskLayer->setOffsetFromRenderer(m_graphicsLayer->offsetFromRenderer());
     }
@@ skipping 86 matching lines @@
         if (style->shouldPlaceBlockDirectionScrollbarOnLogicalLeft())
             clientBox.move(renderBox->verticalScrollbarWidth(), 0);
 
         IntSize adjustedScrollOffset = m_owningLayer->scrollableArea()->adjustedScrollOffset();
         m_scrollingLayer->setPosition(FloatPoint(clientBox.location() - localCompositingBounds.location()));
         m_scrollingLayer->setSize(clientBox.size());
 
         IntSize oldScrollingLayerOffset = m_scrollingLayer->offsetFromRenderer();
         m_scrollingLayer->setOffsetFromRenderer(-toIntSize(clientBox.location()));
 
+        if (m_childClippingMaskLayer) {
+            m_childClippingMaskLayer->setPosition(m_scrollingLayer->position());
+            m_childClippingMaskLayer->setSize(m_scrollingLayer->size());
+            m_childClippingMaskLayer->setOffsetFromRenderer(toIntSize(clientBox.location()));
+        }
+
         bool clientBoxOffsetChanged = oldScrollingLayerOffset != m_scrollingLayer->offsetFromRenderer();
 
         IntSize scrollSize(renderBox->scrollWidth(), renderBox->scrollHeight());
         if (scrollSize != m_scrollingContentsLayer->size() || clientBoxOffsetChanged)
             m_scrollingContentsLayer->setNeedsDisplay();
 
         IntSize scrollingContentsOffset = toIntSize(clientBox.location() - adjustedScrollOffset);
         if (scrollingContentsOffset != m_scrollingContentsLayer->offsetFromRenderer() || scrollSize != m_scrollingContentsLayer->size()) {
             bool scrollingCoordinatorHandlesOffset = compositor()->scrollingLayerDidChange(m_owningLayer);
 
@@ skipping 1233 matching lines @@
     } else if (graphicsLayer == m_ancestorClippingLayer.get()) {
         name = "Ancestor Clipping Layer";
     } else if (graphicsLayer == m_foregroundLayer.get()) {
         name = m_owningLayer->debugName() + " (foreground) Layer";
     } else if (graphicsLayer == m_backgroundLayer.get()) {
         name = m_owningLayer->debugName() + " (background) Layer";
     } else if (graphicsLayer == m_childContainmentLayer.get()) {
         name = "Child Containment Layer";
     } else if (graphicsLayer == m_maskLayer.get()) {
         name = "Mask Layer";
+    } else if (graphicsLayer == m_childClippingMaskLayer.get()) {
+        name = "Child Clipping Mask Layer";
     } else if (graphicsLayer == m_layerForHorizontalScrollbar.get()) {
         name = "Horizontal Scrollbar Layer";
     } else if (graphicsLayer == m_layerForVerticalScrollbar.get()) {
         name = "Vertical Scrollbar Layer";
     } else if (graphicsLayer == m_layerForScrollCorner.get()) {
         name = "Scroll Corner Layer";
     } else if (graphicsLayer == m_scrollingLayer.get()) {
         name = "Scrolling Layer";
     } else if (graphicsLayer == m_scrollingContentsLayer.get()) {
         name = "Scrolling Contents Layer";
     } else {
         ASSERT_NOT_REACHED();
     }
 
     return name;
 }
 
 } // namespace WebCore